Editors may be contributed as usual using a org.eclipse.ui.editors extenstion point. For all script language editors exists ScriptEditor abstract class. It already has standard editor features like folding support, standard actions, word navigation, bracket matching, outline page and more.
There are important things, that concrete editor implementation should provide. First thing it a "text tools". So you should implement all ScriptTextTools abstract methods. They may return partition scanner, semantic highlighing strategies, source viewer configuration and more.
Source viewer configuration is a second important thing. If you'll use ScriptSourceViewerConfiguration as base, you'll fetch "for free" a quick outline view, documentation hovers, hyperlinks support.